A device of such type originates, for example, from U.S. Pat. No. 5,549,448. In order to adjust the radially extending stator blades of a stator blade ring of a compressor, an adjusting ring, which is concentric to the center axis of the compressor, encompasses its center casing. Each stator blade of the stator blade ring, which is rotatable around its longitudinal axis, is connected in each case by a pivoted lever to the adjusting ring which is rotatable in the circumferential direction. The rotation of the adjusting ring in the circumferential direction brings about a rotation of the stator blades around the respective longitudinal axis by means of the pivoted lever. As a result, the adjusting ring is moved in the circumferential direction by adrive device, which at the same time supports the adjusting ring.
An adjusting ring which is rotatable in the circumferential direction for adjusting the stator blades of a ring, is also disclosed in EP 1 524 413 A2.
Furthermore, it is known to radially support the adjusting rings on the stator blade carrier in each case by roller blocks, wherein the adjusting rings can move freely in the circumferential direction on the rollers of the roller blocks. On account of the fact that the material temperature of the stator blade carrier in operation is higher than that of the outside adjusting ring, a radial relative movement ensues between stator blade carrier and the adjusting ring. The magnitude of the relative movement increases on account of the temperature which increases from stage to stage of the stator blade carrier. In order to prevent the loading of the contact points between the rollers and the bearing surface of the adjusting ring from increasing unacceptably on account of this relative movement, the roller blocks are flexibly supported on disk spring packs. The disk spring packs, however, allow a movement of the adjusting ring in the axial direction on account of the axial forces which arise from the reaction forces of the adjustable blades. This leads on one hand to flow losses in the compressor on account of the asymmetrically or differently adjusted stator blades of the ring, as the case may be, when viewed over the circumference, and on the other hand also leads to wear on the support of the adjusting ring and also on the adjusting ring itself.